Alkyl substituted aromatic sulfonates



Brightness Relative to MgOi'l.

April 12, 1949. HUNT ETAL 2,467,131

ALKYL SUBSTITUTED AROMATIC SULFONATES Filed 001:. 15, 1947 2 Sheets-Sheet 1 PIC-3.1.

Brightness Relative to Mg0,%

Detergent Concentration in 52 FIG.I[.

.0 ,lO/o 5/o .257. .3570

' Detergent Concentration in INVENTORS .MAD/SONHUNT" V/KTOR WEINMA YRafld MAR/0 FRANCESCO SARTORI Saw-81% ATTOR EY Brightness Relative to M90,

April 12, 1949. M. HUNT El'AL 2,467,131

ALKYL SUBSTITUTED AROMATIC SULFONATES Filed Oct. 15, 1947 2 Sheets-Sheet 2 FIGJJI.

Brighthtss Ralativeto mom .h

. Detergent Concantrufion in INVENTORS MAD/SON HUN T,

VIK TO I? WEINM'A YRdfld MAR/0 FRANCESCO SARTOR/ ATTORNEY Dchrqcn-t Conccntrotionin Patented Apr. 12, 1949 v a 2,467,131

UNITED STATES PATENT OFFICE ALKYL SUBSTITUTED AROM'ATIC SULFONATES Madison Hunt, Claymont, Del., Viktor Weinmayr, Pitman, N. J., and Mario Francesco Sal-tori, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application October 15, 1947, Serial No. 780,097

Claims. (Cl. 260-505) 1 2 This invention deals with a group of alkylarotion, the term water-soluble shall be construed matic sulfonic acids and their salts useful as suras meaning that the compound concerned is soluface'active agents, particularly as detergents and ble in water to an extent of at least 0.2% by wetting agents. weight.

It is an object of this invention to provide new 5 The products of this invention are prepared by detergent compounds of superior practical propsulfonating the corresponding hydrocarbon ,with erties, especially as regards detergent power and oleum and, if desired, neutralizing the sulfonic speed of wetting. acid thus formed with an alkali-metal hydroxide,

The use of alkylated aromatic sulfonic acids as an alkaline-earth hydroxide, orany other alkaline detergents as a general proposition iswell known. agents such as primary, secondary or tertiary Both sulfonated naphthalene and benzene derivaamines or quaternary nitrogenous bases. The tives have been indicated in the art, and the alkylaromatic compounds themselves may be prelength of the alkyl chain has been varied from as pared by any suitable synthesis, such as the low as 3 carbon atoms to as high as 20 carbon Friedel-Crafts reaction or reactions based on a atoms, both straight-chain and branched-chain Grignard synthesis. These methods of prepararadicals being often employed. tion are illustrated in the following examples,

We have now found that the limited group of which however are given merely for illustrative compounds having the particular structure depurposes, without any intent to limit the invenfined hereinbelow possesses outstanding qualities tion thereby. as detergents, being superior to hitherto described The annexed drawings represent graphically compounds as regards detergent power at low the data obtained in our detergency tests on the concentrations in hard water. In addition, these novel compounds and reported in the tables herecompounds possess very good wetting speed, which inbelow.

' adds to their superior value from the viewpoint Emma.E mm

of practical use.

The novel compounds embraced in this inven- A- Sy t e is the hydrocarbon tion are characterized by possessing a sulfonated To a mixture of 50 parts of m-xylene and 15 m'xylene ring fii is 'f fi' to g 'gg parts of anhydrous hydrogenfluoride maintained atom of norma am a mm 0 at 0-5 C. in a copper vessel, 10 parts of decene-l bon atoms, the point of attachment of the alkane are added lowl with sti T m to Said my] ring being m position para to one agitated fo r 18%0111'5 at t en iperaftiire f of g i 9; g gi The mixtu're is poured slowly into 500 parts of ice poun S o s nven on are e e y 9 water, and the upper organic layer is separated formula on and washed with 5% sodium carbonate solution. After removal of the excess xylene by distillation, the product is distilled. The yield of material x boiling at 115-122 C. at 3 mm. pressure is 12.8 parts. The compound gives a refractive index of b 'n *=1.4906 and density of H1 D=0.8603 wherein R is a straight-chain, saturated aliphatic hydrocarbon radical of 8 to 11 carbon atoms, whfle Suljommon X represents the sulfonic acid radical or a salt To 15 parts of the above pr 2 Parts f t g oleum are added slowly with agitation and cool- This invention embraces the above compounds in 80 as to h ld h temperature at 2030 C. in free acid form as well as in the form of water- Af all f t oleum has been added. the

soluble salts thereof, as obtained for instance perature of the reaction mixture is raised to 40- by neutralizing the free acid with inorganic or C. and held at this temperature for one-half organic bases. For the purpose of this invenso hour. The productispo 9 P rts'oi water and parts of alcohol is added in order to obtain a homogeneous solution. The mixture is drum dried to yield 50 parts of product containing about 40% active ingredient and 60% sodium sulfate. The active ingredient may be isolated in magnesium hydroxide, ammonia, moirioethylamine, dimethylamine, trimethylamine, tetramethylammonium hydroxide, the corresponding ethylamines, the various ethalonamines (mono-, diand tri-), etc.

EXAMPLE 2.-PREPARATION on THE HYDROCARBON BY GRIGNARD SYNTHESIS To a suspension of 14.9 parts of magnesium in 600 parts of anhydrous ether are added 97.8 parts of n-octyl bromide in 100 parts of dry ether. The addition requires about two hours and is carried out at such a rate that the ether boils gently. The mixture is then refluxed for one additional hour. A solution of '74 parts of 2,4-dimethylacetophenone (A. Claus, Ber., 19,230) in 100 parts of dry ether is slowly added and refluxing is continued for one hour after addition is complete. The reaction mixture is then poured into ice water and acidified with hydrochloric acid. The upper layer is separated and washed with sodium carbonate solution. The ether is removed by distillation, and the residue is heated at 200 C. with 30 parts of potassium acid sulfate for 2 hours. The product is then decanted from the potassium acid sulfate and distilled. The material boiling at 135-140 C. at 10 mm. pressure is collected. This material, which represents 56 parts, is a mixture of 2-(2,4-dimethylphenyl) -decene-1 and 2- (2,4-dimethylphe'nyl) -decene-2.

The above product is dissolved in 100 parts of glacial acetic acid and 0.1 part of platinum catalyst (Organic Synthesis, vol. I, page 452) are added. The mixture is reduced with hydrogen at three atmospheres pressure and at a temperature of 30-50 C. The catalyst is removed by filtration and the acetic acid, by distillation. The mass is then vacuum distilled and the product boiling at l35-136 C., at 10 mm, pressure, is collected. The yield is 48 parts. The product has the same physical properties as the 2-(2,4-dimethylphenyl) -decane obtained in Example 1 by hydrogen-fluoride alkylation. Analysis: Calculated for CiaHao; C==8'I.81, H=-12.19. Found, C=87.34, H=12.50.

This product is then sulfonated and neutralized as described in Example 1.

EXAMPLE 3 The procedure is the same as in Example 2. except that 111 parts of n-decyl bromide are employed in lieu of the octyl bromide therein mentioned. 2-(2,4-dimethylphenyl)-dodecane is obtained, which is then sulfonated and neutralized as in Example 1.

EVALUATION or m1: Pnonucra The evaluation 01' the above products for wetting power has been carried out as described in the A. A. T. C. Year Book for 1948, page 230. The wetting power is gauged by the concentration in grams of active ingredient per liter of solution necessary to wet in 25 seconds. In Table IA below, this concentration is designated as the standard wetting concentration. For detergency evaluation, the method described by O. C. Bacon, American Dyestuii Reporter, vol. 34, pages P556- P561, has been used. The results are expressed in tabular form using the per cent reflectance of light from the surface of the soiled fabric relative to the reflectance of magnesium oxide as a measure of brightness. The detergency is tested at five different concentrations. For the purpose of these tests, water was employed containing 360 P. P. M. of alkaline earth chlorides calculated as calcium carbonate.

Usinng these methods, the products of this invention show outstanding detergency at low detergent concentration in hard water. This is a real advantage even though at high concentrations other closely related structures may have approximately equal activity. In addition to outstanding detergency, the products have outstanding wetting speed. This is advantageous since it enables the use of the same compound when either washing or wetting action is desired.

The following Table I illustrates the superior ity of the 2,4-dimethylphenyl compounds over the corresponding phenyl derivatives as detergents in hard water. I

The above data are reproduced graphically in Figure I, wherein the individual curves have been designated a, b, c, and d to correspond with the items in the above table. It will be noted that curves 0 and d drop considerably below curves a and b in the region of low concentrations. This brings out the efiect of the p-methyl substituent in the benzene ring. When in addition, the benzene ring carries also a methyl group in the 2-position, a marked improvement in wetting speed is obtained. This is the principal advantage of the 2,4-dimethylphenyl compounds over the 4-methylphenyl derivatives of our copending application Serial No. 780,096, and is brought out by the data in Table IA 'hereinbelow.

The position or the dimethyl groups on the phenyl rings is important, as illustrated by the following Table 11.

TABLE II.

Detergent Concentration inpercent -3 Compound I g 0.050.100.15 0.25|0.35

(41) Sodium sulionate oi 2-(2,4-dimethylphenyl)-decan 36 48 49 50 51 51 (e) S ium sulfonete 2-(2,5-dimethylphenyU-decane 36 37 42 47 61 51 Q) So um sulfonate ofv 2-(2,5-dimethylphenyl)-2,6,8,8-tetramethylnonene'. 36 38 44 49 49 49 (9) Sodium snlionate oi 2-2.5-dimethyiphenyD-Z-methyl ecane. 86 36 38 42 69 60 The data in this table are reproduced graphically in Figure II, the curves being marked to correspond.

The contribution of a straight aliphatic chain to outstanding detergency is shown in Table III below:

Tarts III Detergent Concentration in percent Compound Graph No.

Sodium suiionete of 2-(2,4-dimetbylphenyD-decene Sodium sulionate oi condensation product of m-xylene with propyiene totremer For corresponding curves, see Figure III. The position of the 2,4-dimethylphenyl group in the alkane chain is important to detergency', as shown by the following Table IV.

TABLIIV Detergent Concentration inpercent 5, Compound g 0 |0.05|0.10 0.15025 0.35

(0) Sodium sulionate oi 2-(2,4-di- I methylphenyD-decane B6 48 49 60 51 61 (k) Sodium suiionate of 6-(2,4 dimethyiphenyD-undecene 36 36 36 38 41 41 alkaline compounds to give the corresponding sulfonates. Of these, the sodium sulfonates are the preferred compounds; however, the potassium calcium, ammonium and various amine or quaternary ammonium salts are also suitable.

The products of this invention are useful as detergents and wetting agents. The products show unusually high detergency at low concentrations in hard water and in addition have good wetting speed. It is expected that in practical use the concentrations employed will generally The corresponding graphs are given in Figure It will be understood that many variations are possible in the methods of synthesizing the novel compounds and in the choice of bases for neutralizing the sulfonic acid groups. Apart from the last-mentioned freedom of variation, however, the number of sulfonic acids falling within the scope of this invention is limited and is represented in fact by the following 4 compounds: 2-(2,4-dimethylphenyl) -decanesulfonic acid 2-(2,4-dimethylphenyl) -undecanesulfonic acid 2-(2,4-dimethylphenyl) -dodecanesulfonic acid 2-(2,4-dimethylphenyl) -tridecanesu1fon1c acid These suli'onic acids may be neutralized with fall within the limits indicated in the above tests.

We claim as our invention: 1. A compound of the general formula om-on-n Ha wherein R is a straight-chained alkyl radical of 8 to 11 carbon atoms, while X designates a radical selected from the group consisting of the sulfonic acid group and water-soluble salts thereof.

2. The alkylated, m-xylene alkali-metal sulfonates characterized by the formula CHc-CH-R Hg wherein R is a straight-chained alkyl radical of not less than 8 and not more than 11 carbon REFERENCES crm The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,161,173 Kyrides June 6, 1939 2,199,131 Flett Apr. 30, 1940 2,244,512 Brandt June 3, 1941 7 OTHER REFERENCES Suter: "Organic Chemistry of Sulfur," Wiley 0; Sons, Inc., New York, New York, 1944, p e 206.

Certificate of Correction Patent No. 2,467,131. April 12, 1949.

MADISON HUNT ET AL.

It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 6, lines 15 and 28, claims 1 and 2 respectively, for that portion of the formula reading GIL read CH and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 13th day of September, A. D. 1949.

JOE E. DANIELS,

Assistant Gammissioner of Patents. 

